Studies were made with alkaline and acid detergent solutions at three temperatures (20, 45, and 70 C) and four milk concentrations (0.00, 0.0.1, 0.10, and 1.0%). Turbidity measurements were made continuously while the solutions were circulating through a piping system. The turbidity of milk-detergent-water solutions was found to be primarily influenced by the concentration of milk. As little as 0.01% milk caused a significant change in turbidity (1.4%), and the percentage of transmittance decreased an average of 78.6 when 1% milk was added to the water that contained the detergent. Detergent concentrations and temperature of the solutions had only minor effects on turbidity. Formation of precipitates by action of phosphates in hard water did not decrease the sensitivity of the method to added milk.
1Contribution from the University of Missouri Experiment Station, Journal Series No. 7047. Trade names and names of commercial companies are used in this publication solely to provide specific information. Such mention does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture or an endorsement by the Department over other products not mentioned.